Deteriation of cavity wall ties

[bof]

In message , Steve writes

It was around £5k, that's in some years back prices, and they were big walls. I think took a couple of blokes a few days, not sure as we hadn't moved in at the time.

[Steve]

seems quite straightforward and I am confident that I can do as good, if not better job than contractors.

Obviously, I will not know the tricks of the trade but I expect to learn some quite quickly.

Excellent advice! SWMBO will, hopefully, see that I do need a *serious* drill and bits for this work. The rest of your description of the work is crystal clear and makes very good sense. I am used to working from ladders so that should be OK.

Steve

[Hugo Nebula]

On Sun, 26 Nov 2006 15:20:27 GMT, a particular chimpanzee named randomly hit the keyboard and produced:

I think they were more common in larger houses close to the coast. Not so much inland & in working class housing. From what I've seen, they used slate to tie the leaves together (which obviously doesn't tolerate movement very well) and had thin cavities.

It was also common to have a 'solid' wall with snapped headers. Any cavity in these walls is just as a result of the two leaves spreading apart.

[Andrew Gabriel]

Interesting -- a brickie mentioned this to me when bricking up the bottom of a window in my 1909 house, but I never heard of it since then until you mentioned it. The house construction was flemish garden wall bond, which he matched (complete with lime mortar) in his brickwork. I questioned him snapping most of the headers and he said it was to create a small damp-proof cavity, and that somewhere around half of the headers in the walls would have been snapped originally for the same reason.

[Peter Hemmings]

Sorry I have only got the last part of this thread and might not be relevant! FYI I have a 50's semi with wire wall ties and I had to be very careful when I bought the house. There was a major problem with the ties being incorrectly treated and they got affected by the lime in cement resulting in walls actually parting!! Many houses near to me have nice little "dots" on walls where they have been replaced. I understand this was a general problem in houses built around the mid fiftys.

[Phil L]

It can be a problem in any building built before the mid nineties when stainless steel was introduced, even the galvanised butterflies used prior to this are not exempt from corrosion, mostly due to brickies' habit of bending them to suit the block height by using a trowel and breaking off the zinc coating

[Bob Mannix]

Again just for interest, my previous house (c 1928) has cavity downstairs (standard gap) and solid upstairs (rendered). Wall ties are cast iron, in the shape of a semicircle with horizontal prongs coming out at right angles to the ends (IYSWIM). Still in good nick.

One advantage of this construction is that the upstairs walls are thinner with the difference being on the inside, which meant there was a useful ledge round the stairwell, avoiding the need for long paper drops and providing support for a working platform.